ArcGIS Pro 2.6 API Reference Guide
Legend Property (LegendStyleItem)
Example 

ArcGIS.Desktop.Mapping Namespace > LegendStyleItem Class : Legend Property
Gets or sets the ArcGIS.Core.CIM.CIMLegend of the legend style item.
Syntax
public CIMLegend Legend {get; set;}
Public Property Legend As CIMLegend
Exceptions
ExceptionDescription
This property must be called within the lambda passed to QueuedTask.Run
Example
LegendStyleItem legendItem = null;
CIMLegend legend = await QueuedTask.Run<CIMLegend>(() =>
{
  return legendItem.Legend;
});
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

LegendStyleItem Class
LegendStyleItem Members